1. Field of the Invention
The present invention relates to a plasma display panel and method for manufacturing the same, and more particularly to a method of forming a barrier rib-forming layer and lower dielectric layer using a glass powder.
2. Description of the Related Art
Plasma display panels (PDPs) are flat panel display devices that display images or information using a plasma discharge. PDPs generally are divided into DC-types and AC-types according to the panel structure and driving method. In addition, the PDPs generate visible rays obtained from the energy difference when an ultraviolet ray generated due to the plasma discharge of a gas (such as He, Xe, etc.) provided in each cell excites a phosphor lining in the cell, which emits a visible photon when returning to the ground state.
Further, PDPs have advantages such as an easy manufacturing process, simple structure, high brightness, high luminous efficiency, memory capacity, and a wide viewing angle of over 160°. PDPs are also used in 40+ inch wide screens. The PDP generally includes an upper substrate and an oppositely disposed lower substrate, barrier ribs, and cells defined by the two substrates and barrier ribs.
In addition, transparent electrodes are disposed on the upper substrate, and bus electrodes are disposed on the transparent electrodes to reduce the resistance of the transparent electrodes. Address electrodes, which are also called data electrodes, are formed on the lower substrate.
Also, the cells divided by the barrier ribs are lined with phosphors. An upper dielectric layer is disposed on the upper substrate to cover the transparent electrodes and the bus electrodes, and a lower dielectric layer is disposed on the lower substrate as to cover the address electrodes. In addition, a protection layer including magnesium oxide, for example, is disposed on the upper dielectric layer.
The barrier ribs are present to maintain a discharge space between the upper and lower substrates, and also to prevent electrical, optical cross-talks between the adjacent cells. The formation of the barrier ribs is an important step in manufacturing quality PDPs. This is especially true as the size of panels grows larger and larger.
In general, the barrier ribs are formed using a Sand Blasting method, Screen Printing method, or Photo Etching method. In the Sand Blasting method, the address electrodes and the dielectric layer are first formed on the lower substrate, and then a glass paste is applied thereon and is used to form the barrier ribs, followed by a sintering process. Then, a stripe type mask pattern is disposed thereon, and fine sand particles are sprayed with high speed through the mask pattern, thereby forming the barrier ribs. However, the equipment used in the Sand Blasting method is expensive. The Sand Blasting method is also relatively complex and tends to cause cracks during the sintering step, because a considerable physical impact is applied to the lower substrate.
In the Screen Printing method, the address electrodes and the dielectric layer are formed on the lower substrate, followed by a stripe type screen being disposed thereon. Subsequently, printing is performed repeatedly with a glass paste used in forming the barrier ribs until the barrier ribs with a desired thickness are obtained, and sintering is performed thereafter. However, the Screen Printing method requires the screen-printing step be repeated to obtain the barrier ribs with a desired thickness, because one screen-printing step is insufficient. This repetitive process renders the process complex.
In the Photo-etching method, the address electrodes and the dielectric layer are first formed on the lower substrate, and then a paste used to form the barrier ribs is applied thereto. Then, a stripe type of mask pattern is positioned, and then the barrier ribs are shaped by etching an exposed portion through openings of the mask with an etching agent, followed by sintering. However, in the Photo-etching method, the process is delayed because the paste has to be applied several times to shape a desired thickness of barrier ribs. Also, it is difficult to obtain the barrier ribs having a sufficient structurally and mechanically stable shape to retain a discharging space because the side portions of the barrier ribs are over-etched.
Therefore, the related art method for forming the barrier ribs is complex, time-consuming and expensive. Further, it is difficult to form barrier ribs with a desired shape and mechanical strength.